As World War II rages on, Honey Deschamps tediously transcribes decrypted signals from the German Army, doing her part to assist the British war effort. Halfway across the world, Hitler’s armies are marching into Leningrad, leaving a trail of destruction and pillaging the country’s most treasured artworks, including the famous Amber Room. As reports begin filtering into Bletchley Park about the stolen loot, Honey receives a mysterious package postmarked from Russia. Inside is a small piece of amber, and it is just the first of several such packages. When she examines them together, she realizes that someone, relying on her abilities to unravel codes, is trying to tell her something.